The following _does_ work:
// file ccall.c
int some_weirdly_named_func(int p)
{
return(p += 10);
}
Run
# file ccaller.nim
{.compile:"ccall.c".}
proc weirdCcall(p: cint) : cint
{.importc:"some_weirdly_named_func".}
let r = weirdCcall(3)
echo $r
Run
Note that nim _can_ import "some_weirdly_named_func()" as one is free to name
it in Nim as one wishes (in the example `weirdCcall`). One might as well stick
with `some_weirdly_named_func` but then Nim will treat the Nim version as if
one had called it `someweirdlynamedfunc` \- but still call the correct C
function.